Distribution of full motion video data has evolved from early television broadcasting to meet viewer demand. Earliest video distribution was by point-to-point wiring between a camera and a video monitor. This was followed by scheduled television broadcasting of programming over the public air waves. In the 1960s, Community Antenna Television (CATV) was chartered to provide off-air television signals to viewers in broadcast reception fringe areas. Later, under FCC regulation, the CATV industry was required to provide local access and original programming in addition to off-air broadcast signal distribution.
In response, several sources of cable network programming were established. Because of the wide bandwidth available on cable television systems, additional channels were available for the new programming. However, programming was generally prescheduled, with the viewer left to tune to the designated channel at the appointed time to view a particular program.
To increase revenues, cable television systems have initiated distribution of premium channels viewable only by subscribers having appropriate descramblers. The subscriber tunes the descrambler to receive a premium channel, descramble the video and audio information and supply a signal capable of reception on a standard television set. Pay-per-view programs, which evolved later, include recently released movies, live concerts and popular sporting events. Subscribers wishing to view a pay-per-view program place an order with the cable operator. At the designated time, the subscriber's descrambler is activated by some control from the cable operator to permit viewing of the pay-per-view programming. However, the subscriber is still restricted to viewing the programming at the scheduled time. There is no capability of delivering programming to a subscriber on demand, that is, immediately or at a subscriber-specified time and date.
More recently, several different wideband digital distribution networks have been proposed for offering subscribers an array of video services, including true Video On Demand service. The following U.S. Pat. Nos. disclose representative examples of such digital video distributions networks: 5,253,275 to Yurt et al., 5,132,992 to Yurt et al., 5,133,079 to Ballantyne et al., 5,130,792 to Tindell et al., 5,057,932 to Lang, 4,963,995 to Lang, 4,949,187 to Cohen, 5,027,400 to Baji et al., and 4,506,387 to Walter. In particular, Litteral et al. U.S. Pat. No. 5,247,347 discloses a digital video distribution network providing subscribers with access to multiple service providers through the public switched telephone network.
As the digital networks evolve to provide equal access to multiple service providers, the network functionality approaches a video "dial tone" functionality somewhat analogous to the dial tone call-up functionality available through the telephone network. FIG. 10 is a block diagram of one type of broadband network for providing interactive services, such as video on demand, home shopping or purchasing, home banking, medical information, ticket ordering, gaming, etc. from a plurality of service providers. The illustrated network is an improvement over the network disclosed in the above noted Litteral et al. Patent.
In the network shown in FIG. 10, the customer premises equipment (CPE) consists of a set top terminal type Digital Entertainment Terminal (DET) 700 and a telephone (POTS or ISDN). The connections to the network utilize Asymmetrical Digital Subscriber Line (ADSL) frequency division multiplexing technology, typically over twisted wire pair. The ADSL connection provides a 1.5 Mb/s downstream video information channel, a two-way telephone connection and a two-way 16 kbit/s control channel. The ADSL technology is described in more detail in the Litteral et al. Patent. The illustrated Video Dial Tone network architecture may use some form of fiber extension in the actual subscriber loops, to provide from a central office (see e.g. U.S. patent application No. 08/233,579, in the name of Bruce Kostreski, filed Apr. 26, 1994 and entitled "Extended Range Video On Demand System". In the illustrated network, the drop to the subscriber's premises is always a wired ADSL loop.
In the network of FIG. 10, the DET 700 connects to an ADSL multiplexer/demultiplexer 701 similar to the in-home ADSL unit in the above discussed Litteral et al. Patent. Each ADSL subscriber line 703 will connect to an ADSL bay 705 located in or associated with the subscriber's local telephone company central office. For each subscriber line 703, the ADSL bay 705 includes an ADSL multiplexer/demultiplexer similar to the central office ADSL unit in the above discussed Litteral et al. Patent.
The ADSL bay 705 provides transport for voice signals on the subscriber loop to and from the associated voice switch 707. The ADSL bay 705 also connects to an access concentrator 709 for providing two-way signaling connections through an X.25 type packet switched data network 711. The ADSL bay 705 also receives broadband digital signals for downstream transport over the ADSL line 703 to each subscriber's premises from a digital cross connect switch 713, labelled "Access DCS" in the drawing. One ADSL line to the home carries one channel of video programming and provides a single output channel. The output channel can provide a video signal to a VCR or to the TV set 700'. The various Access DCS switches throughout the network are controlled by switch controller 712.
If the ADSL bay 705 is local, i.e. located in the same telephone company central office as the cross connect switch DCS 713, the ADSL bay 705 connects to the Access DCS 713 via an appropriate number of local DS1 connections 715. In service areas where an ADSL bay does not carry enough traffic to warrant an associated Access DCS, the ADSL bay will be located in a remote central office facility. Such a remote ADSL bay connects to the Access DCS 713 via a SONET type optical fiber link 717 providing an appropriate number of multiplexed channels to service the number of subscribers connected to the particular ADSL bay.
The Access DCS 713 provides both point-to-point connections and point-to-multipoint connections. Individualized interactive services, such as Video On Demand, home shopping/purchasing and banking, use point-to-point connections wherein the Access DCS connects one broadband input port from a VIP's server to one output port going to the subscriber's ADSL line. Narrowcast and broadcast services utilize point-to-multi-point connections of one input port to a plurality of output ports.
The illustrated architecture of the Video Dial Tone network utilizes two levels of gateways, both of which will communicate with subscribers' DETs via the X.25 data network 711 and the signaling channel on the ADSL subscriber loops 703.
The level 1 gateway 721 performs a variety of network connectivity related functions, including communications port management of transmissions of information between subscribers and servers, processing of billing information and session management. Normally, each subscriber accesses the level 1 gateway (e.g. to select and access a particular VIP's server) by operation of a remote control device which causes the subscriber's DET 700 to transmit data signals to the level 1 gateway via the 16 Kb/s control channel and the X.25 packet switched data network 711. The level 1 gateway transmits one or more selection menus to the subscriber's DET 700 as screens of text data carried by the same path back through the network.
A level 2 gateway provides a number of services for the Information Providers. These services include transmission of menus of available information to subscribers, searches of available information, targeted advertisement insertion, previews, trailers, etc. The level 2 gateway will download video or audio menus to each subscriber's DET for display, thereby allowing each subscriber to select desired information. Once a subscriber makes a selection, the level 2 gateway will signal the appropriate server to schedule transmission of the selected information through the established downstream video transmission path.
The Video Dial Tone network of FIG. 10 provides video on demand and closely related interactive multimedia services. For example, using the upstream data channel, the subscriber can send a request for a particular movie, and the VIP's server will retrieve and transmit that movie as an MPEG digital data stream on the 1.5 Mb/s downstream channel to the digital audio/video processor in the subscriber's DET 700. The DET converts the digital data stream to a signal for driving a standard television set for real time viewing of the movie by the subscriber.
When the subscriber turns on the DET 700, the loader routine and/or operating system within the DET will control wake up, and the DET will transmit an initial message intended for the level 1 gateway. In the network of FIG. 10, the message is carried over the 16 kbit/s signaling channel on the ADSL subscriber's line. The access concentrator 709 uses the X.121 address of the level 1 gateway 721 and the X.121 address associated with the calling subscriber's line 703 to initiate an X.25 packet data call to the level 1 gateway 721. As part of this call, the access concentrator 709 packetizes each message from the DET 700 and adds header information to facilitate transport through an assigned virtual circuit through the X.25 network 711 to the gateway 721. In response to the initial message, the level 1 gateway 721 transmits ASCII text representing one or more pages of a VIP selection menu back to the DET 700 through the assigned virtual circuit through the X.25 network 711 and the signaling channel on the subscriber's line 703. Upon receipt of the menu data, the DET 700 would display an initial selection menu on the subscriber's television set 700'.
The subscriber may review the menu on their television set, and then input a selection using the infrared remote control device, either by moving a cursor to an appropriate point on the screen and hitting &lt;ENTER&gt; or by inputting digits followed by &lt;ENTER&gt;. In response to the VIP selection input, the DET 700 will transmit an appropriate data signal upstream through the network to the level 1 gateway 721.
As part of the X.25 call set up procedure, the access concentrator 709 identified the subscriber and included an X.121 address for the X.25 network port assigned to the subscriber in the initial signaling packet sent through the X.25 network. The level 1 gateway 721 receiving X.25 packets of DET signaling data therefore knows the X.121 address of the calling subscriber. The level 1 gateway 721 uses that information together with the VIP selection input to initiate an X.25 data call to the VIP's level 2 gateway to ask if the subscriber is a valid customer of the particular VIP. If the level 2 gateway indicates that the subscriber is valid, the level 1 gateway 721 initiates a call through switch controller 712 to instruct the appropriate digital cross connect switch DCS 713 to set up a downstream broadband link from the VIP's file server to the subscriber's DET 700 and drops the X.25 communication link to the DET. At approximately the same time, the VIP's level 2 gateway initiates an X.25 packet data call to the subscriber's DET 700. Completion of set-up of both the broadband link and the X.25 signalling link to the DET establishes an interactive video session between the VIP's gateway and server system 752 and the subscriber's DET 700.
Once a session is established, the level 2 gateway executes a two-way communication with the DET 700 through the X.25 network 711 and the signaling channel to obtain a selection or other relevant input from the subscriber. In response, the level 2 gateway provides a signal to the associated file server instructing the server to initiate transmission of selected audio/video program materials from memory through the output port which the DCS 713 has currently connected to the subscriber's line 703. The connection through the DCS routes the downstream broadband transmission to the ADSL bay 705, and within that bay, to the ADSL multiplexer/demultiplexer serving the subscriber's line for transmission over the line 703. The ADSL multiplexer/demultiplexer 701 demultiplexes the broadband signal carrying MPEG encoded audio/video material and applies that signal to the subscriber's DET 700 for decoding and display on the television set 700'.
A more detailed description of the network of FIG. 10, with particular emphasis on the network control functionality of the level 1 gateway, appears in commonly assigned U.S. patent application Ser. No. b 08/304,174 filed on Sep. 12, 1994 entitled "LEVEL 1 GATEWAY FOR VIDEO DIAL TONE NETWORKS", the disclosure of which is incorporated herein in its entirety by reference.
Although the final drop into the subscriber's home is over telephone lines and some of the network equipment resides in telephone company central office buildings, the prior art video dial tone network makes no use whatsoever of routing control functionality of the existing telephone network. The gateways and servers are all separate components newly developed and added over and above the telephone network. Development and deployment of such new equipment adversely impacts the cost of implementing the video dial tone network.
Also, the use of gateways in the manner discussed above results in multiple call switching to set up a single interactive broadband session between a service provider (VIP) and the subscriber's DET. Specifically, the X.25 communication between the DET and the level 1 gateway is a first call. The X.25 communication between the level 1 and level 2 gateways to determine the validity of the calling subscriber is a second call. The switch controller 712 typically comprises another data communication system to permit the level 1 gateway to control a plurality of DCS switches. The instruction to set up a broadband link through a selected DCS therefore may also be viewed as another data call, i.e. between the level 1 gateway and the particular DCS 713 which will provide the switched broadband connection. The two-way X.25 signaling connection between the level 2 gateway and the subscriber's DET would be a fourth call, and the fifth and final call through the network would be the actual broadband link downstream from the server to the DET. Such multiple switching is an inefficient use of resources and consumes excessive time during initial set-up of sessions between the DET and the service provider's equipment.
Concurrent with recent developments in digital distribution of broadband services, the telephone industry has been developing an enhanced telephone network, sometimes referred to as an Advanced Intelligent Network (AIN), for providing a wide array of new service features (see for example commonly assigned U.S. Pat. No. 5,247,571). In an AIN type system, local and/or toll offices of the public telephone network detect one of a number of call processing events identified as AIN "triggers". For ordinary telephone service calls, there would be no event to trigger AIN processing; and the local and toll office switches would function normally and process such calls without referring to the central database for instructions. An office which detects a trigger will suspend call processing, compile a call data message and forward that message via a common channel interoffice signalling (CCIS) link to an Integrated Service Control Point (ISCP) which includes a Multi-Services Application Platform (MSAP) database. If needed, the ISCP can instruct the central office to obtain and forward additional information. Once sufficient information about the call has reached the ISCP, the ISCP accesses its stored data tables in the MSAP database to translate the received message data into a call control message and returns the call control message to the office of the network via CCIS link. The network offices then use the call control message to complete the particular call. An AIN type network for providing an Area Wide Centrex service, for example, was disclosed and described in detail in commonly assigned U.S. Pat. No. 5,247,571 to Kay et al., the disclosure of which is entirely incorporated herein by reference. U.S. Pat. No. 5,241,588 to Babson, III et al. discloses graphical approaches to creating and implementing new customer service procedures for individual customers of an intelligent telephone network.
To date, the AIN telephone network has been a separate technical area of development, with at most limited interaction between the AIN and the video networks. For example, U.S. Pat. No. 4,763,191 to Gordon et al. discloses a method for providing a nationwide dial-a-view service in which a caller desiring a given viewing selection dials an INWATS "800" dial-a-view number for ordering that selection through the telephone networking arrangement. A central data base system provides the originating toll office with routing instructions for sending the request to network services equipment. The network services equipment acknowledges the caller's request for cable services and processes the dial-a-view request. The network services equipment provides relevant data to cable television distribution equipment to control actual supply of requested programming to the calling subscriber. Separate vendor equipment supplies the requested programming to the calling customer via activation of an addressable decoder at the calling customer's television. The telephone network components still do not directly control actual routing of program materials through the broadband network.
As another example, U.S. Pat. No. 5,278,889 to Papanicolaou et al. discloses a two-way video telephone system using a combination of a two-way cable television distribution system and an intelligent voice telephone network. The video distribution networks used apparently are existing frequency division multiplexed analog transmission systems. As part of the disclosed call processing, a central database responds to video telephone call dialing information by providing instructions to the network to route the video portion of the call through a digital inter-exchange carrier network between points of presence of two of the cable television distribution networks.
From the above discussion of the prior art it becomes clear that a need still exists to more closely integrate elements of the existing AIN telephone network into the new video dial tone networks, particularly for purposes of controlling routing through the video dial tone network.